I've been given a PW-3G401M which is said to be the same hardware as the TP-Link MR3020 and TP-Link WR703N, and asked to put OpenWRT on it. However, when I attempt to upload an OpenWRT firmware, I get this message back:

Error code: 18005
Upgrade unsuccessfully because the version of the upgraded file was incorrect. Please check the file name.

I've been told that this is likely related to what Proware calls a "Customer Code", and to ask if the OpenWRT community has any special instructions on flashing TP-Link builds onto comparable/identical Proware devices.

Anybody know where I should be looking here?